The German patent DE 19609048 C2 discusses a heating and air conditioning device for motor vehicles. The heating and air-conditioning device includes a first fluid circuit, which encompasses a heat conductor, a pump and a heat source for heating the fluid, and air is applied to the heat conductor on the secondary side and a blower is provided to generate an air flow. In addition, the heating and air conditioning device includes cooling circuits provided with an evaporator, a condenser and a compressor, as well as a control unit for regulating the cooling circuit as a function of at least one signal from a temperature sensor and an adjustable setpoint value.
The heating and air-conditioning device discussed there also includes a second fluid circuit, which is able to be connected via a valve by the first fluid circuit, the second fluid circuit having a thermo-accumulator as well as a pump, and a heat source in the first fluid circuit is a heating device which is independent of a vehicle operation and used to heat the air flowing through the heat conductor and/or to charge the thermo-accumulator with thermal energy. In the system, the evaporator of the cooling circuit is thermally coupled to the heat conductor by the second fluid circuit and used for charging the thermo-accumulator with cooling energy.